Compensating and fractionating swing grinder hood



July 20, 1954 c. B. SCHNEIBLE ET AL 2,683,958

COMPENSATING AND FRACTIONATING SWING GRINDER HOOD Filed Dec. 31, 1952 2 Sheets-Sheet l INVENTORS:

ATTURNEYS.

y 1954 c. B. SCHNEIBLE ET AL 2,633,953

COMPENSATING AND FRACTIONATING SWING GRINDER HOOD Filed Dec. 31, 1952 2 Sheets-Sheet 2 I N VEN TQRS BYMp ATTORNE Y5 Patented July 20, 1954 COMPENSATING AND FRACTIONATING SWING GRINDER HOOD Claude B. Schneible, Detroit, and Alvin S. Lundy, Huntington Woods, Mich; said Lundy assignor to said Schneible Application December 31, 1952, Serial No. 328,903

8 Claims.

This invention relates to a compensating and fractionating swing grinder hood. The invention is useful also in connection with other devices.

In the operation of a swing grinder, considerable dust, forei n particles, and other material are formed. Should the dusty material around the device be withdrawn from the building, a substantial amount of heat is lost, while at the same time very little protection is offered to the operator handling the grinder. There has been a need for many years for means which will protect the operator through a curtain of air or other gas against the dust, foreign particles, etc. while at the same time fractionating a portion of the material for removal while separating another relatively clean portion and recycling in a way which will protect the operator, etc.

An object of the invention is to provide a hood structure which accomplishes the above desired results and overcomes the disadvantages referred wheel while also fractionating air sections containing particulate matter and recycling a relatively clean portion of the air for forming an air curtain about the grinder. A still further object is to provide, in combination with a suspended grinder, a hood permitting movement of the grinder and the flexible support therefor within the hood, while at the same time directing the curtain of air about the grinder at an open end of the hood and reusing a substantially uncontaminated portion of the air for forming a curtain about the grinder. Other specific objects and advantages will appear as the specification proceeds.

The invention is shown, in an illustrative embodiment, by the accompanying drawings, in

which- Figure 1 is a top plan View of a hood structure embodying our invention; Fig. 2, a front view in elevation; and Fig. 3, a vertical sectional view, the section being taken as indicated at line 3-3 of Fig. 2.

In the illustration given, IE) designates a, casing forming a chamber I' l therein adapted to receive a swing grinderfl.

In the specific illustration given, the swing grinder tool I2 is supported in a balanced position by the depending flexible element H, which may consist of a chain, wire, or any other suitable supporting element. At the forward end of the tool is mounted a motor M, which drives through a shaft within the tube [5 the grinder wheel It. The grinder wheel and mechanism l2 are supported upon a hand1e-equipped frame IT at the rear or entrance end of the casing Hi. The operator may stand holding the handles it? and operate the grind-er tool. Since the grinder tool is well known in the art, a further detailed description is herein believed unnecessary.

As stated above, the casing HI provides a compartment about the major portion of the grinder tool and the top wall IQ of the casing 10 is provided with an opening 20 receiving the flexible element l3 carried by a, support in the building well above the hood. W e prefer to provide casing l 0 at its rear open end with converging side walls 2| about the grinder, so as to direct air int-o the chamber! I.

At the rear wall or any side wall of the casing i0 we provide fractionating outlets, whereby a heavier body of air or a body of air containing a larger proportion of particulate matter may be withdrawn through one conduit, and another body of air or gases, substantially free of such particulate matter or containing very little particular matter or other contamination, may be withdrawn and recycled to form a curtain about the grinder and thus to protect the operator from particles leaving the grinder. In the illustration given, we provide an outlet 22 and a conduit 23 leading therefrom. Conduit 23 may be provided with a fan for withdrawing the material therethrough or the conduit 23 may communicate with a chamber in which suction is maintained, as, for example, a dust collector, washing column, etc.

Vertically spaced above the outlet 22 is a second outlet 24, with which a duct 25 communicates. The duct 25 leads into a horizontal conduit 26 equipped with a fan 2?. From the discharge end of fan 27 the air is discharged through a pair of inclined passages 28 and 29, which are spaced apart and which provide an opening 3% therebetween receiving the flexible suspension element [3. The opening 3i? thus permits the flexible element [3 to swing in a relatively wide area as the grinder wheel I8 is manipulated. The forward ends of passages 28 and 2B, which not only move laterally but also are narrowed upwardly, lead into a plenum or distributing chamber 35, which is provided at its lower side with a wide discharge opening 32. In entering the chamber 3!, the air passes through spaced grills 33 and thence downwardly through adjustable louvers 34. For example, louvers such as shown in Schneible Patent No. 2,292,665 and Schneible Patent No. 2,277,271 have proven very satisfactory. Adjustable deflectors 35 are provided for directing the air about the grinding wheel !5 and thus providing a curtain of air between the operator and the wheel. A deflector 36 is supported upon the tool l2 and arranged for an angular position directing the heavy particles toward the floor of the hood.

Operation In the operation of the apparatus, the operator manipulates the grinder tool in the usual manner, the suspension element l3 allowing free movement of the tool as the element moves within the open area (it in the hood portion thereabove. As the dust or cloud of particulate matter is formed, the heavier material settles to the bottom of the chamber, while a higher strata of material containing particulate matter is drawn off through conduit 3 to a dust collector, washing tower or to any other disposal point. The higher strata of air or gas, ich contains very little contamination, is recycled through duct 25 and the casing 26 to the discharge passages 2t and 29. Fan El draws the material through the duct 7:5 and then discharges it through the passages 28 and and plenum chamber 3 l. The air reaching the plenum chamber 'Jl under the force of the is discharged through the louvers 3d and the deflectors 35 to form curtains of air or gas about the grinder i=3. Thus, there is projected between the operator and the wheel a protec""ve curtain, while also the discharge curtain or curtains are effective in driving air and particulate matter 6. wnwardly toward the bottom or the chamber i i. Here, the heavier particles drop out and fall upon the floor. The deflector 3i; aids greatly in directing the heavier particles downwardly toward the floor of chamber Ii, enabling the lighter portion of the air column to rise and be subjected to a further fractionation. The air containing the heavier materials is drawn off through outlet 22 and duct 23, while near the top of the chamber ii the lighter air, substantially freed of dust and other contaminated material, is drawn off and reutilized in the forming of the air curtain. By this means, the warm air which is directed toward the operator and bet "een the opertc-r and the grinder and dust column, is effectively reused to save the heat therein. By the use of the divided air flow structure leaving the fan 2? and toward the plenum chamber 3!, the operator is able to move the grinder with great freedom within the chamber l i. The defiective apparatus, including members 3&- and the plate 38, protect the opening it in the casing ill and the space between the divided conduits 28 and 29 so that there is no tendency for dust-laden air to escape therethrough and substantially all or the air is thus removed through the outlets 22 and 2-5 under the influence of the suction means.

While, in the foregoing description, we have set forth specific structures in considerable detail for the purpose of illustrating an embodiment or the invention, it will be understood that such details may be varied widely by those skilled in the art without departing from the spirit of our invention.

We claim:

1. In an air compensating and fractionating grinder hood structure, a. casing providing a compartment adapted to receive a swing grinder, one side of the compartment being open to permit the operator to operate the grinder therethrough, a pair of superposed outlets in another side of said compartment and separate ducts leading from each, one of said ducts leading from the lower of said outlets to a source of suction for discharging heavier material from said compartment, a second duct leading from the upper of said outlets and communicating with an outlet at the open end of said compartment, and means for producing suction in said last-mentioned conduit and for discharging gas through said outlet at the open end of said casing compartment to form a curtain of air about the grinder.

2. An air compensating and fractionating swing grinder hood, comprising a casing providing a compartment adapted to receive a swing grinder suspended upon a suspension element, one side of the compartment being open to permit the operator to operate the grinder therethrough, said casing having at another side verticallydisposed outlets, a duct equipped with suction means leading from the lower of said outlets, a recycling duct leading from the upper of said outlets, a fan drawing air through the last-mentioned duct and discharging it at the open end of said compartment, and means at the open end of said compartment for directing air downwardly in a curtain toward the grinder.

3. An air compensating and fractionating swing grinder hood, comprising a casing providing a compartment open at one end and having an opening in the top thereof for receiving the suspension element of a suspended swing grinder, one side of the compartment opposite the open end thereof being provided with at least two outlet openings, a duct leading from a source of suction and communicating with the lowermost of said outlets, a duct leading from an upper outlet and extending forwardly to a wide discharge opening extending above the open end portion of said compartment, said second-mentioned duct being divided above the opening in said top wall of the casing to permit said suspension element to swing therebetween, and means for producing suction in said second-"mentioned duct and discharging the returned air flowing therethrough downwardly about the grinder at the open end of said compartment to form a curtain of air about the entrance to the compartment.

4. The structure or" claim 3, in which an inclined deflector plate is supported upon the swing grinder and rearwardly thereof for directing particulate matter toward the floor of the compartment.

5. An air compensating and fractionating swing grinder hood, comprising a casing providing a compartment having an open end and being adapted to receive a swing grinder equipped with a suspension element, the top side of the compartment being open to permit the suspension element to swing therein, fractionating outlets arranged in vertically-spaced relation in the wall of the compartment opposite the open end thereof, a conduit leading from the lower of said outlets and communicating with an area maintained under suction, a second conduit leading from an upper outlet and communicating with a plenum chamber above the open end of said compartment, means for producing suction in said last-mentioned conduit and forcing the recycled air through said plenum chamber, and discharge means from said chamber inclined forwardly and downwardly for forming a curtain of air about the open end of said compartment.

6. The structure of claim 5, in which the recycled warm air is directed by deflectors toward the area between the grinder and the operator.

7. In apparatus of the character set forth, a casing providing a compartment having one side thereof open, air curtain forming means about the open end of said compartment for directing air across the opening, another side of said casing about said compartment being provided with at least two vertically-spaced outlets, a duct leading from the lower of said outlets to an area maintained under suction, a duct leading from the upper of said outlets to said curtain-forming means, and means for inducing flow of air through said last-mentioned duct and for discharging the same through said curtain-forming means.

8. In abrading apparatus wherein a hood closure receives an abrading device and air is drawn through the hood to carry away the abraded matter, means for fractionating a portion of the air and recycling the same in the forming of an air curtain about said abrading device, comprising a hood having an enlarged opening in an end thereof affording manipulation of said device by an operator, said hood having at least two outlet openings in another wall thereof one above the other, suction means communicating with the lowermost outlet, a duct communicating with the uppermost outlet and extending therefrom to the end of said hood having said enlarged opening, said hood providing an inlet adjacent the end thereof provided with said enlarged opening communicating with said duct and being oriented to discharge air about said device to provide an air curtain thereacross; and means for drawing air through said duct and for discharging it through said inlet.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 965,223 Plant July 26, 1910 1,359,718 McGuire Nov. 23, 1920 2,499,582 Harrison Mar. 7, 1950 2,565,510 Martin Aug. 28, 1951 

